Disclosure: I have translated novels by both Ayatsuji Yukito and Arisugawa Alice.
So this is a bit of a strange book, as this is not a novel per se. Half of the book consists of the murder play, written in screenplay format. The other half includes write-ups and reports on all the other things that happened during the event, from how people arrived on the ship to completely transcribed interviews (and even a transcribed... magic show), as well as photographs of the trip and of the belongings of the authors which had been exhibited at the show. The trip was held twice, once in October 2002, embarking from Tokyo, and once in December of the same year, embarking from Kobe: this book reports on the events on both trips. The general flow of both trips was that people could get on board in the afternoon, after which the ship would depart the harbor. After a while, guests would be shown a video that laid out the basics of the murder game they'd try to solve. They could then find panels on the ship with additional information and the clues needed to solve the murder (for example, panels with close up photographs of the crime scene). In between, there'd also be dinner, with talk panels with the authors and at a certain point, the participants would also be asked to go to either an Ayatsuji or an Arisugawa room, where they'd talk a bit and also provide an exclusive clue to solving the mystery. At the end of the evening, people could fill in a form to guess who the killer was, and the big reveal, and they'd award the person who got the answer right by picking up on all the clues. The book reminded me a lot of Ayatsuji Yukito Satsujin Jiken - Arujitachi no Yakata ("The Ayatsuji Yukito Murder Case - The House of the Owners"), which was also a screenplay-format write up of a murder mystery play in honor of Ayatsuji, accompanied by write-ups on the events around it.
The story of the murder play revolved around Katayama Kippei, an infamous mystery writer who was harshly criticized for his books that were basically plagiarized from other writers. One day, he didn't appear at an appointment, so his wife and his editor visited him in his office, which they found locked from the inside. When they got in, they found Katayama stabbed with a knife and his head resting on a few of his books (like a pillow), his body surrounded by torn pages from the books that were allegedly plagiarized. Oddly enough though, the police discovered the only key to the office in the victim's mouth, so how did the murderer escape? Among the suspects are Ayatsuji Yukito and Arisugawa Alice, as Katayama also published books titled The Hexagon House Massacre and The 64th Locked Room...
To be honest, I only picked up this book because I was interested in the murder mystery supervised by Ayatsuji and Arisugawa, as I have loved a lot of their collaborative work (on Anraku Isu Tantei and Trick X Logic). This story was only supervised by the duo though, and as a mystery story, I ended up not liking it nearly as much as I had hoped. While the backstory of the plagiarizing writer is pretty funny and meta, the actual murder plot is (of course) presented in a rather disjointed manner, with both parts with actual characters and dialogue, but also just still photographs of the evidence and things like the locked room murder element don't really come alive due to the dialogue-heavy set-up of the story, and the fact it was designed as a story where info would presented in several bursts (video/panels etc). I am not a big fan of the trick used for the locked room an sich, though some of the hints for the surrounding mystery are good. Though I guess I do very much miss the big "reveal that changes your look on how things played out" that a lot of the Ayatsuji/Arisugawa duo mysteries pull off greatly, making this one feel a bit underwhelming.
The interviews/talk shows give you some background information on how the men look back at (at the time) 15 years of shin honkaku and of course their work, but I have to admit I was not nearly as interested in the interviews as in the murder play.
The official site for this tour is still online by the way, and it looks DELICIOUSLY early 2000s Japanese website. It would fit right in in Project Hacker...
So Mystery Night is more of an interesting anecdote than something you really need to read if you're looking for Ayatsuji/Arisugawa mystery fiction. The interviews might be of more historical value, as well as the write-ups on what is actually a very unique event (can you just imagine it!? A cruise trip to celebrate a group of authors and the mystery genre!), but I wouldn't bother go looking for this book for the mystery.
